Artificial limb



July 3, 1951 c. N. PACE ETAL 2,559,044

ARTIFICIAL ,LIMB

Filed Feb. 5, 1949 2 sheets-sheet 1 3mm harlesMPace, 15'. 0. Dee/leer,

ATTOR N EY July 3, 1951 c. N. PACE ETAL ARTIFICIAL LIMB 2 Sheets-Sheet 2 Filed Feb. 3, 1949 15'; 0. Deck? Patented July 3, 1951 UNITED STATES PATENT OFFICE ARTIFICIAL LIMB Charles N. Pace and Edward 0. Decker, Cumberland, Wis.

6 Claims.

The present invention relates to artificial legs, and it has for one of its objects to provide an improved article of this nature by means of which thecomfort and safety of the wearer will be bettered.

A further object of the invention is to provide an artificial leg embodying means for the placing. on and removal of the leg.

Another object of the invention is to provide an artificial leg formed with improved means for locking the parts thereof together to prevent buckling or collapsing under the weight of the wearer when a forward step is taken.

Another object of the invention isto provide an artificial leg, the characteristics of which eliminate forward and backward bobbing of the wearer, thereby enabling a walking movement which will more nearly simulate the action of a natural limb than has been possible with artificial limbs of the conventional type.

A still further object of the invention is to provide an artificial leg wherein the parts thereof are readily adjustable and so designed as to give complete confidence to the wearer, particularly in above-the-knee' amputees.

With the foregoing and other objects in View, which will be made manifest in the following detailed description and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein Figure l is a fragmentary elevational view of a portion of the artificial leg as seen from the rear of the wearer;

Figure 2 is a side elevational view of the artificial leg with parts thereof in section;

Figure 3 is a fragmentary side elevational view of the calf portion of the artificial leg with parts broken away to indicate the interior structural features thereof; and

Figure 4 is a detailed sectional view taken substantially on line 44 of Figure 3.

Referring to the drawings for a more detailed description thereof, 6 designates the thigh portion, 1 the calf portion, and 8 the foot portion of an artificial leg. As is to be understood, the artificial leg in accordance with the present invention is designed for above-the-knee amputees, and is adjustably supported on the thigh 9 of the wearer.

The means for supporting the artificial leg includes a belt Ill which completely encircles the body and is held in position by any desired means, notshown. A tension band II is carried by the belt l5, and as shown in Figures 1 and 2 of the drawings, said band II has its ends secured. as

indicated: at [2 and I3 to the belt ill. The band H in conjunction with the straps I4 form the means of adjustably supporting the artificial leg on the wearer. The straps IA are provided with an adjustable loop portion I5 which carries a buckle I6 adapted to be snapped over a hook I"? which is carriedby the thigh portion 6. Adjustment is effected through the loop portion; 15.

As shown'in Figure 1 of the drawings, the tension band H carries. a hook-shaped member [8, to which is connected by means of a buckle I!) an elastic webbing 20. The length of this elastic webbing 261s adjustable through. a buckle 2-! and the purpose thereof will be hereinafter more. fully described. It will be noted; however, that the elastic webbing 20, the hook-shaped member [8 and buckle [9 are located: in the rear of the wearer.

Referring to Figures 2 and 3 of the drawings, it will be noted that the calf portion 1 is hollow and is designed so' as to reduce the weight of. the limb to a minimum and at the same time provide a supporting surface within the interior of. said calf portion for the attachment of. the various parts. which enable the wearer to walkin a natural manner with a free and. easy motion. A plate 22 having spaced upstanding ear portions 23 is riveted or otherwise secured within the calf portion 1, as indicated at 2'4. A bifurcated bracket 25 is pivctally connected as indicated at 26 between the ear portions 23, said bracket being normally disposed at an angle to the plate 22. A toggle lever 2? is pivotally supported. intermediate its ends, as indicated at 28 within the bifurcated end of the bracket 25'. One end of the lever 2'5 is slotted as indicated at 2'8, while the other end is formed with an opening t in which is held a hook 3 1- having oppositely disposed and 33. As will hereinafter appear, movement will be imparted to the lever 21 which will accelerate the forward motion of the calf portion I until it is in line with the thigh portion 8. Furthermore, the lever 2'5 will prevent buckling of the leg portions during walking movement or locking of the leg portions during flexing of the knee.-

Each of the arms 32 and 33 of the hook 3| has attached thereto a strap 32 and 33. These straps have one end formed with loops 52, and 53 for receiving the arms 32 and. 33 respectively. The other ends of the straps. 32' and 33" are secured to the thigh portion 5 as indicated at 54in FigureZ of the drawings.

A roller 34 mounted within a cage 35 is carried in the slot 29. The cage carries a bracket 36 in which is supported a roller 31. A power transfer strap 38 is trained about the roller 31 and is held in position on said roller by means of the bracket 36. One end of the strap 38 is fixedly secured adjacent the upper end of the calf portion 1, as indicated at 39, while the other end of the strap is connected to the buckle 2| of the elastic webbing 20. The intermediate portion of the strap is trained about a roller 40 which is carried in a bracket 41 mounted within a recessed portion 42 of the thigh portion 6.

A strap 43 is fixedly secured as indicated at 44 on the outside of the calf portion 1 in the rear face thereof, said strap 63 extending upwardly in back of the wearer and being attached by any desired means about the shoulders of the wearer. This strap 43, upon movement of the shoulders, will lift the foot from the ground.

The foot portion 8 is formed with a socket or recess 45 for receiving the lower end of the calf portion 1. An actuating cable 46 has one end attached to the lever 2'! by means of a clamp or the like 41, while the other end thereof is attached as indicated at 48 to a coil tension spring 49. The tension spring is carried by a bolt 50 which extends vertically within the heel of the foot portion, and adjustment of the tension is effected through the nut 5|. It will be readily understood that tightening the nut will increase the tension on the spring 49 and cable 46.

From the above description when taken in connection with the accompanying drawings, it will be appreciated that the improved artificial leg is so designed as to enable walking in a natural manner by amputees. On a forward stride of the artificial leg, there will be caused a very pronounced tug on the strap 38. Movement of this strap about the rollers 40 will transfer the power to the roller 34, thereby pulling said roller upwardly to force the lever 21 downwardly at an acute angle. It will, of course, be understood that the initial movement of the forward stride of the leg will cause the calf portion 1 to pivot on the thigh portion 6 about a pivot 55. Thus, as the lever 21 is urged downwardly at an acute angle, there will be created a pull on the straps 32 and 33' which will accelerate the forward motion of the calf portion 1 until it is again brought in line with the thigh portion 6. properly adjusted and during this forward movement just described, the lever 21 when in its acute angular position, will act as a lock to prevent buckling or collapsing of the artificial leg portions. This anti-buckling feature of the lever 21 will be present at all times regardless of the walking pace or the amount of weight or thrust on the heel of the foot portion.

Since the artificial leg of the present invention simulates the actual walking movement, after the calf portion 1 has been brought into alignment with the thigh portion 6, the entire weight of the wearer will be placed on the leg and the le will move into the rearward position, the weight then being transferred onto the toe of the foot. When this occurs the foot actuated cable comes into action and will hold the lever 21 in a safe downward position'through the remainder of the stride until the thrust is finished, at which time the leg is again free to swing. As previously indicated, the foot actuating cable 46 and the tension thereon can be adjusted to meet the requirements of the wearer.

The strap at which lifts the foot has been designed to intentionally or voluntarily retard When the parts are 7 or prevent the forward action of the calf portion 7 when stepping over an obstruction or onto a stairstep or curbing. The hooks l1 and I8 function as a convenient means of removing or positioning the artificial leg since it permits the wearer to position and adjust the belt In prior to the positioning of the artificial leg.

Various changes may be made in the details of construction Without departing from the spirit and scope of the invention as defined by the appended claims.

We claim:

1. In an artificial limb, pivotally connected thigh and calf portions, means operable upon pivotal movement of said thigh portion for accelerating forward motion of the calf portion until it is in line with said thigh portion, said means including a strap having one end supported from the body of the wearer, and its other end attached to said calf portion, a lever pivotally supported within said calf portion, means attached to one end of said lever and connected to said strap for moving said lever downwardly about its pivot, and means attached to the other end of said lever and operable by movement of said lever to accelerate movement of said calf portion into alignment with said thigh portion during a forward stride of said artificial limb.

2. A structure as recited in claim 1, a foot portion on said calf portion, and means in said foot portion connected to said lever for holding said lever locked in its downward position until pressure is released on said strap.

3. A structure as recitedin claim 1, a foot portion, a cable having one end attached to said foot portion and its other end attached to said lever for holding said lever locked in its downward position until pressure is released on said strap.

4. In an artificial leg, upper and lower leg portions pivotally connected together for relative swinging movement therebetween, means for adjustable supporting said upper leg portions on the body of the wearer, a baseplate attached to the inside of said lower legportion, a bracket pivotally connected to said plate, a lever pivotally supported intermediate its ends on said bracket, one end of said lever being formed with an elongated slot, a hook having oppositely disposed arms carried in the other end of said lever, a roller movable in said slot, a second roller supported above and carried by saidmovable roller, an operating strap trained about said second roller and having one end secured to said lower leg portion and its other end adjustable secured to the body of the wearer, and means attached to said hook operable by movement of said lever and strap to accelerate movement of said lower portion into alignment with said upper leg por- 1tion during a forward stride of said artificial 5. A structure as recited in claim 4:, wherein said hook attached means comprises spaced straps having one end secured to said upper leg portion.

6. A structure as recited in claim 4, and a strap secured to the rear face of said lower leg portion and extending upwardly for lifting said leg portion upon relative movement of the wearer.

CHARLES N. RACE. EDWARD O. DECKER.

No references cited. 

